Re: [PATCH v2 1/4] android: binder: Don't get mm from task

From: Arve HjÃnnevÃg
Date: Tue Oct 24 2017 - 14:36:54 EST


On Tue, Oct 24, 2017 at 12:28 AM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, Oct 23, 2017 at 11:18:52AM -0700, Arve HjÃnnevÃg wrote:
>> On Sat, Oct 21, 2017 at 1:15 AM, Greg Kroah-Hartman
>> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>> > On Fri, Oct 20, 2017 at 08:58:58PM -0400, Sherry Yang wrote:
>> >> Use binder_alloc struct's mm_struct rather than getting
>> >> a reference to the mm struct through get_task_mm to
>> >> avoid a potential deadlock between lru lock, task lock and
>> >> dentry lock, since a thread can be holding the task lock
>> >> and the dentry lock while trying to acquire the lru lock.
>> >>
>> >> Acked-by: Arve HjÃnnevÃg <arve@xxxxxxxxxxx>
>> >> Signed-off-by: Sherry Yang <sherryy@xxxxxxxxxxx>
>> >> ---
>> >> drivers/android/binder_alloc.c | 22 +++++++++-------------
>> >> drivers/android/binder_alloc.h | 1 -
>> >> 2 files changed, 9 insertions(+), 14 deletions(-)
>> >
>> > I've applied these first 2 patches, but patches 3 and 4 I have already
>> > applied to my char-misc-next tree, right?
>> >
>> > thanks,
>> >
>> > greg k-h
>>
>> I would expect you got a merge conflict from one of those. Using patch
>> 3 and 4 in from this patchset should avoid that conflict if your
>> eventual 4.15 branch is not based on your current char-misc-next
>> branch.
>
> I've resolved the merge conflict so my char-misc-next branch should be
> all caught up now. It would be wonderful if you could verify this.
>
> thanks,
>
> greg k-h

I have not tested your branch directly, but the relevant code in
char-misc-next is now identical to the code I tested.

--
Arve HjÃnnevÃg